1. Field of the Invention
The present invention relates to paper-making machines, and, more particularly, to air presses within a paper-making machine.
2. Description of the Related Art
A paper-making machine receives a prepared fiber suspension and manufactures a fiber web therefrom. A paper-making machine may in general include a head box, forming section, press section and drying section. The press section typically includes a plurality of press assemblies which apply pressure to the web for the primary purpose of expressing water therefrom. Press assemblies are typically configured as mechanical press assemblies, such as extended shoe nip presses, etc. It is also known to configure a press assembly as an air press including an air chamber which exerts pressure against the fiber web for the purpose of expressing moisture therefrom. Examples of air presses which may be utilized on a papermaking machine are disclosed in U.S. patent application Ser. No. 09/409,287, entitled xe2x80x9cPressing Apparatus Having Semi-Permeable Membranexe2x80x9d now U.S. Pat. No. 6,416,631, and 09/408,691, entitled xe2x80x9cPressing Apparatus Having Chamber and Sealingxe2x80x9d, now U.S. Pat. No. 6,161,303, each of which are assigned to the assignee of the present invention.
Although air press assemblies as described above provide effective pressing of a fiber web, a need still exists to provide a higher capacity air press while at the same time occupying less physical space.
The present invention provides an air press assembly for a paper-making machine, including a single roll which defines two separate air presses.
The invention comprises, in one form thereof, a press assembly for use in a paper-making machine including a roll, a first air press backing assembly and a second air press backing assembly. The first air press backing assembly and the second air press backing assembly each include an inner wall, an outer support structure and a plurality of inflatable hoses interposed between the inner wall and the outer support structure. The inner wall is positioned adjacent to and defines an air chamber with the roll.
An advantage of the present invention is that two separate air presses are provided using a single roll.
Another advantage is that the structure of each air press assembly is simple and easy to manufacture.
Yet another advantage is that the deflection of the inner wall adjacent the roll may be relatively easily controlled using pneumatic hoses between the inner wall and the outer support structure.